1. Field of the Invention
The present invention relates to retaining devices, and particularly to a retaining device which securely retains expansion cards in a computer chassis.
2. Description of the Prior Art
A computer typically includes a chassis that encloses circuit components, such as processors, memory chips, peripheral interface devices and other circuit elements. The core circuit components, such as the processors and the memory chips, are often mounted on a single printed circuit board, such as a motherboard. It is often desirable to provide the computer with expansion ports or slots for attaching additional printed circuit cards (“expansion cards”) having additional capabilities.
In one conventional arrangement, the expansion slots are provided on the motherboard. One drawback with this approach is that the expansion slots occupy valuable space on the motherboard. And nowadays the trend of the computer enclosure is small and thin. So a new type of computer enclosure has a limited height that cannot accommodate an expansion card directly mounted on the motherboard. One approach to addressing this drawback is to attach an intermediate riser card to a single slot of the motherboard and attach a plurality of expansion cards to the riser card.
Generally, The expansion card is horizontally attached on top of the riser card. A support component is applied on a top portion of the riser card to retain the expansion card. Such an arrangement for expansion card is disclosed in U.S. Pat. No. 5,943,215. A support block is mounted on the top of the riser card. The support block is engaged with a clasp extending from one side wall of the classis so that the riser card and the expansion card are retained. Another means is shown in US Patent Application No. 20030016496. Retaining means thereof comprises a bracket mounted on the riser card, which is also locked on one side wall of the classis. A plurality of parallel expansion cards is horizontally attached on the bracket. In assembly, generally, the riser card is directly inserted in the slot of the motherboard, and in disassembly, the riser card is directly drawn out. During these processes, the riser card and the expansion cards are susceptible to be damaged. When the computer is moved to anther place or sustains external shocks, the riser cards and the option cards are prone to be loosed or detached from the motherboard and the riser cards, respectively.